Salt impregnated desiccant matrices for ‘open’ thermochemical energy conversion and storage – Improving energy density utilisation through hygrodynamic & thermodynamic reactor design

•A selection of sorbents were tested for open thermochemical heat storage.•Sorbent performances were experimentally compared in two different reactors.•SIM-3a provided the best cyclic behaviour and thermal performance.•Using meshed tube air diffusers improves sorption heat storage performance.•A linear correlation between heat output and moisture uptake was obtained. In this study, the performance of three nano-composite energy storage absorbents; Vermiculite-CaCl2 (SIM-3a), Vermiculite-CaCl2-LiNO3 (SIM-3f), and the desiccant Zeolite 13X were experimentally investigated for suitability to domestic scale thermal energy storage. A novel 3kWh open thermochemical reactor consisting of new meshed tube air diffusers was built to experimentally examine performance. The results were compared to those obtained using a previously developed flatbed experimental reactor. SIM-3a has the best cyclic behaviour and thermal performance. It was found that 0.01m3 of SIM-3a can provide an average temperature lift of room air, ΔT=20°C over 180min whereas for SIM-3f, ΔT